The invention relates to a cue recording system for magnetic recorders, and more particularly to a cue recording system which records a cue signal in a magnetic recorder such as a conventional tape recorder, dictating machine or the like.
When a magnetic tape, on which an acoustic signal is recorded by a magnetic recorder such as a dictating machine or tape recorder, is loaded on a playback unit such as a transcriber, for purpose of reproducing the recorded acoustic signal, a cue signal is usually employed to provide an indication of a tape portion where a desired message is recorded. The cue signal is magnetically recorded on the tape by an operator of the magnetic recorder so as to be detected during its playback operation. Usually a cue signal is recorded on a tape at a location corresponding to the beginning of a message which is desired to be typewritten or where a particular care should be exercised in hearing, as distinguished from the remainder of the recorded signal. During playback, the tape is played under a rapid advance mode until the cue signal is detected, whereupon the tape is automatically fed at a lower uniform rate for reproducing the recorded signal portion of interest.
The cue signal recorded is detected by a cue detecting head, and since the tape is in its rapid advance mode during the detection of the cue signal, it is necessary that the cue signal be recorded over a certain tape length or over a given period of time. The usual practice of magnetically recording a cue signal on the tape is to depress a pushbutton to close an associated switch, which activates a cue generator for feeding it to a cue recording head, which in turn magnetically records it on the tape. When such scheme is followed, it will be understood that the duration of the recorded cue signal depends on the length of time during which the pushbutton is held depressed, thus failing to provide a recorded cue signal of a given time interval. Specifically, if the pushbutton is immediately released, the cue signal recorded will be of an insufficient duration to permit its detection upon playback, thus causing a failure to locate the intended signal portion. On the other hand, if the pushbutton is held depressed for an increased time period, the cue signal will have an increased duration, causing a waste of the activating current and reducing a tape length which is available for the recording of the acoustic signal.
With a magnetic recorder in which an acoustic signal from a microphone and a control or cue signal are serially recorded on one track of a magnetic tape through a single magnetic head, it is possible for the acoustic input signal to be simultaneously recorded as the cue signal is being recorded. In such circumstances, there again results a failure of locating the intended signal portion during the playback of the tape.